Lithology prediction and storage/transport properties evaluation in clastic sedimentary rocks using seismic velocities

Conference · Fri Feb 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5141144

Vernik, L; Nur, A ^[1]

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1. Stanford Univ., CA (United States)

An extensive database of petrophysical measurements at high effective pressure on a variety of rock types encountered in clastic sedimentary sequences was used to derive new models that describe relations among physical parameters of these rocks. Based on optical microscopy, SEM, and experimental data four major petrophysical groups are considered: (1) clean arenites (clay content C < 3% vol.), (2) altered arenites and arkoses (3% < C < 15%), (3) wackes (35% > C > 15%), and (4) shale (C > 35%). Each of these petrophysical groups is characterized by its distinct mineralogy. The compressional velocity-porosity relation for each of these groups is found to be linear with high correlation coefficients allowing remarkably accurate porosity estimates and lithology prediction from sonic logs, compared to Willie et al.'s time average equation of the linear regression by Han et al., both of which neglect mineralogical and textural factors. On the porosity-velocity plots, each petrophysical group has similar but shifted linear trends of incipient lithification and diagenesis. The incipient lithification in both sandstones and shales is primarily brought about via the formation of small, contact-localized bonds due to the chemical processes at the grain boundary and is characterized by sharp increases in the elastic moduli. This results in dramatic velocity increase while porosity reduction at this stage is very small. Further diagenesis as traced on porosity-velocity plots is characterized by much gentler linear trends reflecting a considerable porosity reduction caused by the temperature-induced processes of dissolution and precipitation.

• OSTI ID: 5141144
• Report Number(s): CONF-9103128-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:2; Conference: American Association of Petroleum Geologists (AAPG)/Society of Economics, Paleontolgists, and Mineralogists (SEPM)/Society of Exploration Geophysicists (SEG)/Society of Professional Well Log Analysts (SPWLA) Pacific Section annual meeting, Bakersfield, CA (United States), 6-8 Mar 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
SANDSTONES
DIAGENESIS
MINERALOGY
POROSITY
SHALES
SONIC LOGGING
DATA ANALYSIS
COMPRESSIBILITY
ELASTICITY
GEOLOGIC MODELS
LITHOLOGY
PERMEABILITY
SEISMIC SURVEYS
WATER SATURATION
WAVE PROPAGATION
GEOPHYSICAL SURVEYS
MECHANICAL PROPERTIES
ROCKS
SATURATION
SEDIMENTARY ROCKS
SURVEYS
TENSILE PROPERTIES
WELL LOGGING
580000* - Geosciences